The Molecular Genetics unit will facilitate the use of state-of-the-art genetic technologies in all of the projects in the Program. The responsibilities of Core D will involve the performance of two separate but related functions: 1) Maintain a Breeding Colony to provide transgenic rats, expressing the mouse Ren-2 gene, for all of the projects in the Program. It is anticipated that the Program will require the production of 700 hemizygous transgenic offspring with a like number of controls each year. This will be accomplished with a 3-stage breeding strategy that will simultaneously produce mRen-2 hemizygotes along with transgene negative littermates to act as controls. The plans for the breeding strategy were originated in conjunction with Dr. Detlev Ganten, a developer of the TGR(mRen-2)27 hypertensive rat strain. Rats will have the transgenic genotype confirmed by with the resources of the Molecular Biology section of the Core. 2) Provide a Molecular Biology Core with the reagents and expertise necessary to facilitate the completion of the molecular biology protocols described in the individual projects. The major activity of this segment of Core D will be to adapt methodologies for the monitoring of gene expression to the specific needs of the projects requiring this level of measurement. Major aims related to the localization and quantitation of gene products involved in the RAS are part of 5 of the 6 projects. In addition to the set-up and performance of the assays, it is envisioned that the Core function will involve a major degree of consultation, information exchange, and instruction directed to the PI's and technical staff of the involved projects so that the repeated procedures can be undertaken directly by the appropriate investigator's personnel. Available technologies to localize and monitor levels of gene expression will include: in situ hybridization of tissue sections and solution hybridization / nuclease protection assays and PCR-mediated detection of cell-specific mRNA production. These functions are intertwined and the activities will be performed by the same personnel.